Hot green building trends Part 1
2013 saw green building move to new heights of innovation and productivity, thanks in large part to products that addresses some of the most compelling challenges in the marketplace.
With a push from the U.S. Department of Homeland Security, resilient construction will have a certification similar to Energy Star ratings for appliances.
Fortunately, a number of construction products offer resiliency or durability as well as energy efficiency.
One such material is in the testing phase right now. It’s a large, polymer home building block, designed by the Paducah, Ky., firm Lok-N-Blok. According to Greg Siener, the firm’s president, the blocks are easy to assemble, don’t rot, and are lighter than cinder blocks.
They’re also remarkably strong, which could prove invaluable during hurricanes, earthquakes, or tornados, Seiner noted. Computer tests showed the blocks withstood winds in excess of 250 mph. Also, the blocks don’t shatter under extreme pressure, unlike cinder blocks.
Lok-N-Blok walls are effective in any climate, with an expected value exceeding R-20 for its insulation rating. Scrap produced from both the manufacturing process and the jobsite can be recycled, incinerated, or disposed of in a landfill without harm to the environment.
Photo courtesy of Lok-N-Blok
Hybrid water heaters
In the quest for ever-greater efficiency in water heaters, companies are combining the best characteristics of the tank and tankless water heater design.
These designs work well in both retrofit and new home installations. For retrofit situations, sometimes a tankless water heater does not work well because of requirements for larger gas lines. That can make installation costs simply unaffordable.
Grand Hall, marketer of Eternal hybrid water heaters, has hybrid water heater models that don't require gas line upgrades and have a small footprint. That makes them ideal for retrofit installations. The hybrid models feature a two-gallon reserve tank inside and a full flow design that does not impact water pressure for up to two simultaneous household applications.
Photo courtesy of Grand Hall
While green building has long emphasized insulation, recent research by Building Science Corporation showed that air sealing is at least as important as the R-value of the insulation in a building envelope. A 2013 Building Science Corp. report “The Thermal Metric Summary Report,” which compared the performance of various types of insulation, including fiber glass, cellulose, spray foam and extruded polystyrene.
The study showed the primary path for heat transfer is air leakage, or convection. Airleakage can account for up to 40 percent of a building’s energy loss, and it cannot be stopped with traditional insulation.
The study showed that if the wall assembly was effectively sealed from the inside and outside so there was virtually no air movement, the walls performed the same regardless of the insulation type. If there was air movement through the wall, then all types of insulation experienced a loss of thermal performance.
Air sealing can be accomplished with framing techniques as well as spray foam insulation or air-sealing products such as EcoSeal from Knauf Insulation. EcoSeal is water-based spray on sealant to seal around interior framing and envelope penetrations.
Photo courtesy of Knauf Insulation
With improved air sealing, ventilation is as much a part of a high performance home as the R-value. To meet the need for fresh air ventilation in a tight home, building pros are taking advantage of technology like heat recovery and Energy Recovery ventilators, and other fresh-air strategies.
The Proud Green Home at Serenbe is one high performance home that uses an ERV for ventilation as well as supplemental heating. The ERV recovers heat from the inside air before exchanging it for fresh outside air. That helps heat the home, reducing the load on the heating system and also removing moisture from the air.
Photo courtesy of Zehnder America
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Gary Wollenhaupt is an experienced writer and editor, with a background as a daily newspaper reporter as well as corporate and agency public relations and marketing. He is constantly looking for affordable green upgrades to make to his home in eastern Kentucky.www